I recently bought a Q6600, an Asus P5K-E and 4*1gb PC6400 ram for a new file and vmware server. The board has six sata ports controlled by ICH9R. I have attached six WD 200GB sata disks to these ports and configured a ~1TB RAID5 array using all of the six disks. I was aware that performance night not be stellar with onboard RAID5, BUT using HDtach3 I get an average of 6MB/s and Sisoft Sandra XII shows around 13MB/s average. This is is quite poor performance, but unfortunately real world performance is even worse. Copying files to the array over the network shows more like 0.3-3.0 MB/s (while other disks in the computer usually does around 15-35 MB/s when copying over the network).
I know that stripe size and starting sector of the partition can influence alot and I've tried stripe sizes of 16k, 64k and 128k. as array initialization takes 15-36hrs depending on the stripe size, I haven't yet had time to try out all combinations and having the partition start at sector 2048 (instead of 63) has only been tried with 64k stripe size.
I have tried with and without write back cache activated, but the difference is almost neglible.
I'm running Win2003 ES with all updates, newest drivers and newest bios.
Is this performance level normal for this configuration? Is there anything I can to to make it better? I'm content with 15-20 MB/s sequential read/write as the partition is just for storing and streaming movies.
Any help and suggestions is highly appreciated.